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/*
* Copyright (c) 2015, Ford Motor Company
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following
* disclaimer in the documentation and/or other materials provided with the
* distribution.
*
* Neither the name of the Ford Motor Company nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "utils/logger.h"
#include "utils/rwlock.h"
namespace sync_primitives {
CREATE_LOGGERPTR_GLOBAL(logger_, "Utils")
RWLock::RWLock() {
// start not write_locked
write_locked_ = false;
}
RWLock::~RWLock() {}
bool RWLock::AcquireForReading() {
try {
rwmutex_.lock_shared();
} catch (boost::lock_error) {
// couldn't lock, return false
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for reading");
return false;
}
return true;
}
bool RWLock::TryAcquireForReading() {
try {
bool result = rwmutex_.try_lock_shared();
if (result == false) {
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for reading");
}
return result;
} catch (boost::lock_error) {
// couldn't lock, return false
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for reading");
return false;
}
}
bool RWLock::AcquireForWriting() {
// get exclusive lock
try {
rwmutex_.lock();
} catch (boost::lock_error) {
// couldn't lock, return false
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for writing");
return false;
}
// we now have an exclusive lock
write_locked_ = true;
return true;
}
bool RWLock::TryAcquireForWriting() {
try {
bool result = rwmutex_.try_lock();
if (result == false) {
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for writing");
} else {
write_locked_ = true;
}
return result;
} catch (boost::lock_error) {
// couldn't lock, return false
LOG4CXX_ERROR(logger_, "Failed to acquire rwlock for writing");
return false;
}
}
bool RWLock::Release() {
if (write_locked_) {
// If we have exclusive access, release it
write_locked_ = false;
rwmutex_.unlock();
// lock is now free
} else {
// Otherwise release our shared access
rwmutex_.unlock_shared();
}
return true;
}
} // namespace sync_primitives
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